Assess the impact of supporting SHA256
We need to assess the impact required to support SHA256 in Gitaly as we are currently trodding in the dark with regards to the required effort to support the new hash function. This issue tracks assessing this impact in the context of Rails so that we can arrive at a better estimation at what the effort will be. This will likely both include the technical side of things to support the new hashes, but potentially also the UI-side given that the new hashes are longer and may thus break current limits.
UPDATE:
We can start by identifying breakages from end to end tests, and create an issue to fix each breakage.
There are likely many places in Rails tests themselves that we'll also have to fix, but fixing the e2e tests gives us a good starting point as that are clear breakages of functionality.
Exit criteria for this issue are a set of issues created and added to the epic based on breakages of e2e tests.